Ukraine in pictures: Threat of war between Ukraine and Russia

Russia has reportedly issued an ultimatum to Ukrainian forces - 'surrender or we attack'. More Russian armoured troops have been seen massing on the border of Crimea Monday as frantic diplomatic efforts continue.
Here, Russia's President Vladimir Putin, centre, accompanied by Russian Defence Minister Sergei Shoigu, front left, walks to watch military exercises upon his arrival at the Kirillovsky firing ground in the Leningrad regionPicture: Reuters